Under The Microscope

THE CONCISE OXFORD DICTIONARY OF EARTH SCIENCES, ed by Ailsa Allaby & Michael Allaby; Oxford University Press 1991; 431 pages; $29.95

The true test of a dictionary is whether it's got the sort of words in it that you need to look up. If you're a student of the earth sciences, then this should be the dictionary for you.

Like all dictionaries, it tends a little towards the cryptic, forsaking clarity for brevity. I think Alfred Wallace deserves more than to be listed in passing as a contemporary of Darwin, given his importance in the genesis of natural selection.

As the editors note in their preface, however, it is necessary to differentiate between being a dictionary and an encyclopaedia. The extensive cross-referencing makes this more than the former; the terseness, less than the latter. For an inexpensive reference text, the editors have chosen the right approach.

The other difficult matter with which the editors have had to contend is defining what is an Earth science. They have achieved a startlingly comprehensive coverage -- the neighbouring entries gale, galena, Galilean satellites and gamma rays provide a brief indication of this breadth.

Scrabble devotees may be familiar with aa (that very useful type of lava), but only specialists will be concerned with conjugate fault sets or Zosterophyllophytina. If those sorts of things do interest you, then you would do well to supplement your reference shelf with this text.

Vicki Hyde, NZSM